Timekeeper

Baker Standish would rather do anything than stand in front of a history classroom full of disinterested teenagers. He chose a career outside of academia. His mentor, Professor Bill Jamison, suggested Lineal Chronology as the ideal career choice for a US History major.
Baker Standish was overwhelmed by his new responsibilities. A Timekeeper's duties were far reaching, farther than he could have ever imagined. One of the hazards of the job was something HR Manager Kara Leflar called Timekeeper confusion. Between the confusion and his persistent earworm, Baker wondered if his career choice was a good one.
Against a backdrop of his own reality, Baker engages in mission after mission to set the links in the chain of events that create reality in the proper order. Someone is messing with the clock and it's a constant struggle to reset it.